Typewriter ribbon spool construction



Aug. 25, 964 E. o, SPRADLIN 3,

TYPEWRITER RIBBON SPOOL CONSTRUCTION Filed Nov. 15, 1962 Ja I lnvelitor autumn rzmllin 57 Hill, We, 65Zcnell Attorneys United States Patent 3,145,823 TYPEWRITER RIBBON SPOOL CONSTRUCTION Erdman 0. Spradlin, 544 N. Belleforte, Oak Park, Ill. Filed Nov. 13, 1962, Ser. No. 236,817 3 Claims. (Cl. 197-175) This invention relates to a typewriter ribbon spool, and more particularly relates to a separable typewriter ribbon spool construction having a replaceable ribbon carrying core.

One of the recurring expenses associated with the operation of a typewriter is that occasioned by periodic replacements of the ribbon. Because of the fact that when it is necessary to replace the ribbon, the spool upon which the ribbon is wound is usually also replaced, the total replacement cost is increased by the amount of the spool. In large oifices and other establishments where many replacement ribbons are used daily, the inventory expense for stocking ribbons for each machine as well as the expense of such discarded spools is substantial.

In view of the foregoing, various types of typewriter ribbon spool constructions have been advanced in an effort to eliminate such inventory expenses as well as the cost of the discarded spool. Some of these employ an inexpensive core element to which the typewriter ribbon is attached, the core and ribbon being discarded when the ribbon is worn out. However, for various reasons, such spool constructions have not proved satisfactory nor gained general acceptance.

Accordingly, it is a general object of the present invention to provide a novel and improved typewriter ribbon spool construction employing a replaceable ribbon carrying core.

Another object of the invention is to provide a novel and improved typewriter ribbon spool construction of the foregoing character wherein only the ribbon carrying core need be replaced when it is necessary to change ribbons.

A further object is to provide a novel and expendable typewriter ribbon carrying core adapted for use with a separable typewriter spool construction.

Still another object of the invention is to provide a novel and improved separable typewriter ribbon spool and replaceable ribbon carrying core which is simple in construction, easy to operate, economical to manufacture, and readily adaptable for use with various types of typewriters.

Other objects and advantages will become apparent from the following detailed description and accompanying drawing, in which:

FIG. 1 is an enlarged vertical sectional view of a typewriter ribbon spool and replaceable core construction embodying the features of the present invention;

FIG. 2 is an exploded perspective view of the spool construction illustrated in FIG. 1;

FIG. 3 is a top plan view of the replaceable core portion of the spool construction illustrated in FIG. 2;

FIG. 4 is a side elevation view of the replaceable core illustrated in FIG. 3; and

FIG. 5 is a reduced perspective view showing an alternate construction for the spool portions of the present invention.

In FIGS. 1 and 2, a typewriter ribbon spool construction embodying the features of the present invention is illustrated. For the purposes of the present description the spool construction 10 is shown mounted on a suport spindle indicated at 11 in dotted lines in FIG. 1 of a typical typewriter. Such a spindle may comprise a central guide or shaft portion 12 and one or more upstanding drive pins or dogs 13 extending upwardly 3,145,823 Patented- Aug. 25, 1964 from a support surface, indicated at 14, of the spindle. It will be understood that the spool construction 10 may be adapted for use with other type of drive arrange ments such as are employed in the more common typewriters now in use.

As best seen in FIG. 2, the spool construction 10 generally comprises a pair of spaced circular discs, in this instance an upper disc 16 and a lower disc 17. The discs 16 and 17 may be of any suitable material but are preferably formed of thin gage sheet metal. Each disc may be provided with a central opening 18 for receiving the guide portion 12 (FIG. 1) of a support spindle 11 when the spool is installed on a typewriter. The lower disc 17 may include one or more openings, indicated at 19, for receiving the drive pins 13. Such openings 19 may also be provided in the upper disc 16 to permit interchangeability of the discs.

I-nterposed between the disc 16 and 17 is a replaceable ribbon-carrying core member 21 having a typewriter ribbon indicated at 22 wraped therearound. According to the present invention, the core 21 is in the form of a cylindrical sleeve or bushing and is of a semirigid or resileint material, such as resinous plastic, or the like. The core 21 has an axial length substantially equal to and preferably somewhat greater than the width of the ribbon 22. The core 21 may be provided with any of the conventional ribbon anchors or hooks for securing the end of the ribbon 22 to the core.

An anchor particularly adapted for use with the core 21 i illustrated in FIGS. 3 and 4 and indicated at 24. The anchor 24, in this instance, comprises an elongated piece of metal forced thru the side wall, indicated at 25 (FIG. 4), of the core 21 with the inner end of the metal piece split longitudinally to provide a pair of arms 26 and 27 which are spread in opposite circumferential directions for engagement with the inner surface indicated at 28, of the side wall 25. The anchor 24 may also include a laterally extending struck-out finger or arm 29 for engaging the outer surface of the core 21, and the outer end, indicated at 31, of the anchor may be formed with a barb and bent to a position paralleling the outer surface of the core in the manner illustrated in FIG. 3.

In order to releasably secure the spool discs 16 and 17 to the ribbon carrying core 21 to provide a complete spool assembly, novel interengaging means is provided on the discs 16 and 17 and the core 21. Thus, in the embodiment illustrated in FIGS. 1 and 2, such means comprises at least one and preferably three circumferentially spaced lugs or fingers 34 extending axially from the side faces of the discs 16 and 17, and an annular groove 32 formed in each end face, indicated at 33, of the core 21. In the present instance, the lugs 34 are formed from struck-out portions of the material of each disc. Preferably, the lugs 34 have an axially length substantially equal to or somewhat less than the depth of the grooves 32 and are arcuate in cross section. The radius of curvature of the lugs 34 is substantially equal to that of the grooves 32.

In order to insure firm but releasable engagement between the lugs 34 and the grooves 32, the latter preferably have a radial width somewhat less than the thickness of the material of the lugs 34. Because the core 21 is of a semi-rigid material, such as plastic, the grooves 32 Will deform when the lugs 34 are inserted, thereby providing the desired frictional engagement when the parts are assembled.

The core 21 may include one or more notches or recesses 36 to permit the latter to be used in typewriters having a drive mechanism arranged in this location. In such an installation, only the core 21 and its associated ribbon 22 need be used.

In FIG. an alternate spool disc construction 37 is illustrated, the disc 37 in this instance being the lower disc of a pair. In this embodiment, the disc 37 is provided with an axially extending tubular portion 38 which comprises a portion of the interengaging means. Each tubular portion 38 has a diameter substantially equal to that of the grooves 32 and an axial length substantially equal to but somewhat less than the depths of the grooves 32. The radial width of the wall of the tubular portion 38 preferably is somewhat greater than the width of the grooves 32 to permit tight frictional engagement when the parts are assembled. The disc 37 may be provided with openings (not shown) for receiving the drive mechanism of an associated typewriter, in the manner of the previous embodiment.

With the foregoing construction, it will be apparent that after the initial purchase and installation of the typewriter spool construction 10, whenever it is necessary to change ribbons it is only necessary to remove the spool 10, separate the discs 16 and 17 and the core 21 having a Worn-out ribbon 22 therearound, and discard both the core and ribbon. Thereafter, a new core 21 containing a fresh ribbon may then be readily mounted between the discs 16 and 17 by inserting the lugs 34 into the grooves 32 and applying sufiicient pressure to the discs to cause the lugs to seat in the grooves. The assembled spool may then be installed in the typewriter in the usual manner. Thus, after the initial purchase of the spool construction which includes the discs 16 and 17, only the core 21 containing a fresh ribbon need be replaced. A substantial savings is thus realized each time it is necessary to replace a ribbon.

I claim:

1. A typewriter ribbon spool construction, comprising a pair of spaced discs each having an axially extending portion, and a tubular core of semi-rigid resilient material interposed between said discs and adapted to receive a typewriter ribbon therearound, said tubular core having an annular groove in each end face thereof, each of said grooves being formed by two adjacent concentric walls, said grooves being of a lesser width than the radial thickness of said axially extending portions such that the latter are frictionally retained by the former when inserted therein by virtue of the resiliency of said material, whereby said discs are releasably secured to said core to permit replacement of said core when an associated typewriter ribbon carried thereby is exhausted.

2. The combination of claim 1, in which a plurality of said axially extending portions are provided on each disc, said portions being circumferentially spaced and arcuate in cross section, the radius of curvature of said sections being substantially equal to that of said groove.

3. The typewriter ribbon spool construction of claim 1, in which said axially extending portions are tubular and have diameters substantially equal to the diameter of the groove in the corresponding end face of said core.

References Cited in the file of this patent UNITED STATES PATENTS Re. 11,097 Ray July 22, 1890 602,241 Pendleton Apr. 12, 1898 802,189 Haskins Oct. 17, 1905 806,229 Young Dec. 5, 1905 1,954,848 Scott Apr. 17, 1934 2,389,965 Eckel Nov. 27, 1945 3,045,800 Landgraf July 24, 1962 3,051,287 Grafton Aug. 28, 1962 FOREIGN PATENTS 674,781 Great Britain July 2, 1952 

1. A TYPEWRITER RIBBON SPOOL CONSTRUCTION, COMPRISING A PAIR OF SPACED DISCS EACH HAVING AN AXIALLY EXTENDING PORTION, AND A TUBULAR CORE OF SEMI-RIGID RESILIENT MATERIAL INTERPOSED BETWEEN SAID DISCS AND ADAPTED TO RECEIVE A TYPEWRITER RIBBON THEREAROUND, SAID TUBULAR CORE HAVING AN ANNULAR GROOVE IN EACH END FACE THEREOF, EACH OF SAID GROOVES BEING FORMED BY TWO ADJACENT CONCENTRIC WALLS, SAID GROOVES BEING OF A LESSER WIDTH THAN THE RADIAL THICKNESS OF SAID AXIALLY EXTENDING PORTIONS SUCH THAT THE LATTER ARE FRICTIONALLY RETAINED BY THE FORMER WHEN INSERTED THEREIN BY VIRTUE OF THE RESILIENCY OF SAID MATERIAL, WHEREBY SAID DISCS ARE RELEASABLY SECURED TO SAID CORE TO PERMIT REPLACEMENT OF SAID CORE WHEN AN ASSOCIATED TYPEWRITER RIBBON CARRIED THEREBY IS EXHAUSTED. 